Lithium-ion-conducting materials

A lithium ion conducting ceramic material having the general formulation:

• MI1+x+4z−δMIIIxMIVayMIVb2−x−y−zP3O12
• wherein MI comprises Li, Na, or mixtures thereof;
• wherein 0.05<x<0.5, 0.05<y<2, 0≦z<3, 0<δ<0.5;
• wherein MIII comprises Al, Hf, Sc, Y, La, or mixtures thereof;
• wherein MIVa comprises Zr, Ge, Sn, or mixtures thereof;
• and
• wherein MIVb comprises Ti.

A lithium ion conducting ceramic material having the general formulation selected from (i)

• MI1+x+z−δMIIIxMIVayMIVb2−x−yMVzP3−zO12
• and (ii)
• MI1+x+4z−δMIIIxMIVayMIVb2−x−y−zP3O12,
• wherein MI comprises Li, Na, or mixtures thereof;
• wherein 0.05<x<0.5, 0.05<y<2, 0≦z<3, 0<δ<0.5;
• wherein MIII comprises Al, Hf, Sc, Y, La, or mixtures thereof;
• wherein MIVa comprises Zr, Ge, Sn, or mixtures thereof;
• wherein MIVb comprises Ti;
• MV comprises Si, Ge, Sn, or mixtures thereof;
• and
• wherein the lithium ion conducting ceramic material is hermetic to helium gas.

A lithium ion conducting ceramic material having the general formulation:

• MI1+x+4z−δMIIIxMIVayMIVb2−x−y−zP3O12
• wherein MI comprises Li;
• wherein 0≦x≦0.5, 0≦y≦2, 0≦z≦3, 0<δ≦1;
• wherein MIII comprises Al, Hf, Sc, Y, La, or mixtures thereof;
• wherein MIVa comprises Zr, Ge, Sn, or mixtures thereof;
• and
• wherein MIVb comprises Ti.

A lithium ion conducting ceramic material having the general formulation:

• MI1+x+4α−βMIIIxMIVayMIVb2−x−y−αMVzP3−zO12
• wherein MI comprises Li;
• wherein 0.05≦x≦0.5, 0.05≦y≦2, 0≦z≦1, 0.05<α≦0.5, 0<β≦1;
• wherein MIII comprises Al, Hf, Sc, Y, La, or mixtures thereof;
• wherein MIVa comprises Zr, Ge, Sn, or mixtures thereof;
• wherein MIVb comprises Ti. and
• wherein MV comprises Si, Ge, Sn, or mixtures thereof.